Optimization of Coagulation Process for Qula Rennet Casein by Response Surface Methodology

In this study,Qula was selected as the raw material and Pusillus mucor chymosin was used as the coagulant to prepare Qula rennet casein.Based on the single factor tests,response surface design was used to optimize the coagulation process of Qula rennet casein.Results indicated that the order for affecting the yield of Qula rennet casein was curd pH,chymosin addition amount,CaCl2 addition amount,and curd temperature.The optimal curd conditions included pH 6.2,chymosin addition amount of 0.05 g/kg,CaCl2addition amount of 2.5% and curd temperature of 42 ℃.Under these optimal conditions,the maximum predicted yield was 75.23% compared to 73.54% in the validation experiments.